Toyoda Gosei Co., Ltd.

Kabushiki Kaisha Toyota Chuo Kenkyusho

Toyota Jidosha Kabushiki Kaisha

Sumitomo Wiring Systems, Limited

Autonetworks Technologies, Limited

Shizuoka University

Sumitomo Electric Industries, Co.

Manabu Kagami

Hiroshi Ito

Tatsuya Yamashita

Yukitoshi Inui

Akari Kawasaki

Kuniyoshi Kondo

Masatoshi Yonemura

Shin Sato

Shigeo Hayashi

Hideki Goto

Yasuhiko Takeda

Tadashi Ichikawa

Satoru Kato

Hayato Yuuki

Kazuo Hasegawa

Akari Nakao

Naomichi Okamoto

Hisao Kato

Seigo Takai

Masahiro Tomiki

Eiichi Okazaki

A vehicle network system is provided with a plurality of star networks, a plurality of devices mounted on a vehicle are connected in a star shape through respective branch lines in each of the star networks, and a trunk line for connecting the plurality of star networks, the branch lines are communication lines for optical communications, and the trunk line is a communication line for electric communication.

Vehicle network system

A taper angle of a self-written optical waveguide to be formed is increased or decreased at a desired position. A range of light (aperture number) condensed by a focusing lensis adjusted by an iris diaphragmin which the hole diameter can be changed from 1 mm to 12 mm. An image of the self-written optical waveguidebeing fabricated is taken with a CCD camera, and image processing of the image is executed in real time by an image processing device. The taper angle of the self-written optical waveguideis measured, and the taper angle of the self-written optical waveguidecan be desirably increased or decreased by changing the diameter of iris diaphragm

Fabrication method of self-written optical waveguide

A self-written branched optical waveguide is formed. A laser beamfrom a laser source (not shown) is focused with a lensonto the face of incidenceof an optical fiber. The laser beam of an LPmode was emitted from the face of emergence, and 'bimodal' light intensity peaks were arranged in the horizontal direction (.A). A slide glasscoated with a photocurable resin gelwas placed horizontally (.B). A single linear cured materialwas formed as the LP-mode laser beam was emitted from the face of emergenceof the optical fiber(.C). A branch portionwas then formed at a distance L from the face of emergenceof the optical fiber, which was followed by the growth of two cylindrical cured materialsand. The two cylindrical cured materialsandwere linear branches, and formed an angle of about four degrees. An optical waveguidethus formed was composed of cured materials, and(.D).

Optical waveguide and method for manufacturing the same

A transparent vessel is filled with a mixture solution containing a first photo-curable resin of a low refractive index and a second photo-curable resin of a high refractive index different in curing mechanism. When light at a wavelength capable of curing the first photo-curable resin but incapable of curing the second photo-curable resin is applied to the mixture solution through an optical fiber, the first photo-curable resin can be cured in a state in which the second photo-curable resin is enclosed in the cured first photo-curable resin. Because the refractive index increases according to curing, a self-condensing phenomenon can be generated so that an optical path portion is formed. The optical path portion emits leakage light to its surroundings to thereby form an outer circumferential portion. Then, all uncured resins in the mixture solution are cured. The outer circumferential portion containing a high percentage of the cured first photo-curable resin serves as a clad because the refractive index of the outer circumferential portion is lower than that of the optical path portion.

Material composition for producing optical waveguide and method for producing optical waveguide

In the condition that an acrylic transparent vessel is filled with a curable resin solution capable of being cured by a light, a plastic optical fiber is immersed in the curable resin solution. A laser beam is applied on the curable resin solution through the plastic optical fiber. The curable resin solution is cured gradually by the laser beam applied on the curable resin solution, so that an axial core is formed. Then, the transparent vessel is left at rest for predetermined time, or uncured part of the curable resin solution is removed from the transparent vessel and the transparent vessel is then filled with another curable resin solution. Then, ultraviolet rays are applied on the transparent vessel from the outside of the transparent vessel to cure the residual uncured part of the curable resin solution.

Optical waveguide and method for producing the same

Transparent parallel planar plates which are members for retaining an optical waveguide are provided erectly in an optical path of light in a transparent vessel in advance. An optical fiber is fixed into the transparent vessel while the optical fiber penetrates the transparent vessel, and an optical sensor is also disposed adjustably. Next, a first photo-curable resin solution is injected into the transparent vessel, and light with a predetermined wavelength for curing is emitted from the optical fiber so that the optical waveguide is self-formed by polymerization reaction. Because the parallel planar plates are transparent, the optical waveguide is formed so as to be extended again from the emission ports of the parallel planar plates. Finally, the optical waveguide is formed so as to reach a bottom surface of the transparent vessel. The optical waveguide has a structure in which the optical waveguide is firmly supported at four points in a forward end surface of the optical fiber, the parallel planar plates and the bottom surface of the transparent vessel. Accordingly, a firm optical waveguide device is formed.

Method of manufacturing optical waveguide device

Interference filters which are optical components are erected in advance on optical paths in a transparent container, and the transparent container is filled with a photo-curable resin solution. Further, a jig is prepared for manufacturing an optical waveguide device. The jig includes a housing, and holes. On this occasion, positions of the holes are set such that light input through the hole reaches the holes via the interference filters. Optical fibers are fitted into the holes of the housing and the housing is mounted on the transparent container. Next, light at a predetermined wavelength is guided into the optical fibers so that optical waveguides are formed in the photo-curable resin solution. Next, the photo-curable resin solution is exchanged for a low-refractive-index photo-curable resin solution and then the low-refractive-index photo-curable resin solution is solidified wholly by ultraviolet light. Finally, for example, an optical fiber, a light-receiving element, etc. are provided.

Optical waveguide device manufacturing jig, method of manufacturing optical waveguide device by use of the same jig, and the same optical waveguide device

Into a mixture solutionof a high-refractive-index photo-curable resin A and a low-refractive-index photo-curable resin B, light capable of curing only the resin A is led through an optical fiberso that a cured resinof the resin A having a diameter substantially equal to the diameter of a core portion of the optical fiber is formed so as to extend from a tip of the optical fiber. Then, the residual mixture solutionis cured. In this manner, a module having the previously cured high-refractive-index resinas an optical waveguide can be formed easily. On this occasion, the mixed state of the mixture solutioncan be kept good enough to facilitate the formation of the high-refractive-index resinwhen the solubility parameter &#x3b4;of the high-refractive-index photo-curable resin A and the solubility parameter &#x3b4;and volume fraction &#x3a6;of the low-refractive-index photo-curable resin B satisfy the following expression (4).|&#x3b4;&#x2212;&#x3b4;|&#x3c;&#x2212;7.5&#x3a6;+6.0&#x2003;&#x2003;(4)

Self-formable optical waveguide material composition

An optical fiber, a mixture solution of the photosetting resins polymerizing in two different polymerization types, and a transparent container are prepared. The photosetting resins are not copolymerized, and have different activation wavelengths of the photopolymerization initiators for hardening. Employing a combination in which the activation wavelength of a photopolymerization initiator for a photosetting resin with higher refractive index after hardening is longer than the activation wavelength of a photopolymerization initiator for a photosetting resin with lower refractive index after hardening, a core portion can be only formed by hardening the photosetting resin with higher refractive index due to a difference between two wavelengths. Thereafter, a clad portion can be formed by hardening two kinds of photosetting resins, whereby an optical transmission device can be manufactured.

A method of fabricating an optical waveguide structure includes the step of introducing light into a photo-curable liquid resin. The liquid resin can be a mixture of two types of photo-curable liquid resins having different curing initiation wavelengths and different refractive indexes. The method can include dipping one end of a fiber into the liquid mixture. Light having a wavelength &lgr; can be radiated from the tip end of the optical fiber in order to cure one of the photo-curable liquid resins thereby forming a waveguide. Light having a different wavelength &lgr; can be radiated from an area surrounding the waveguide so as to cure the liquid mixture and form a cladding portion around the waveguide.

Method of fabricating optical waveguide structure

An optical branching device includes a main waveguide and a branching waveguide. A portion of the main waveguide is bent and the branching waveguide is placed close to the bent part of the main waveguide. The branching waveguide has a taper structure such that a width of the branching waveguide is gradually decreased in a propagation direction of light. A central axis of the branching waveguide is tilted from a line extended from a straight part of the main waveguide toward the direction X, or the bending direction of the main waveguide. An input end of the branching waveguide has a normal vector tilted from the central axis of the branching waveguide toward the direction Y, an opposite direction of the bending direction of the main waveguide. With above-mentioned structures, light radiated from the bent part of the main waveguide can be launched into the input end of the branching waveguide and transmitted through the branching waveguide efficiently.

Optical branching devices

A laser Doppler velocimeter in which laser light whose frequency changes continuously at least for a fixed time duration is branched into at least two beams, and the at least two branched beams are respectively transmitted by at least one pair of optical fibers having an optical path difference therebetween, and are focused onto a region to be measured by at least one focusing device. The scattered light of the laser beams focused in the region to be measured are received by a light-receiving device via at least one incident device. At least one Doppler shift frequency in the region to be measured is calculated on the basis of the frequency of a signal of the scattered light received by the light-receiving device, the optical path difference, and a rate of change of the frequency of the laser light. The flow velocity and the direction of the flow velocity are calculated from the calculated Doppler shift frequency.

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Nagoya, Japan

Manabu Kagami